Every single team to win a Super Bowl has needed to get lucky along the way. A key fumble bounced into their hands. A dangerous would-be opponent was eliminated before they could ever match up. A star player narrowly avoided an injury. Luck might be the residue of design, but in the NFL, your luck can also be a product of someone else's subpar design.
Each of the eight remaining playoff teams made brilliant draft picks, found smart coaches, and devoted hours upon hours to scouting the right talent for their roster. They also got lucky. The hands of fate conspired to open up opportunities for organizations to look very smart after the fact.